Circuit interrupting device



'Ncw,` 26, 193521 J. KoPr-:uowlTscH 2,022,241

` CIRCUIT INTERRUPTING EEVICE Filed Mayk 19, 1933 2 Sheets-Sheet l Nov.26, 1935. J. vKoPELlowlTscH CIRCUIT INTERRUPTING DEVICE 2 Sheets-Sheet 2Filed May .19, 1953 S g s Patented Nov. 2s, 193s UNITED STATESg CIRCUITINTERRUPTING DEVICE Jakob Kopeliowitsch, Baden, signor toAktiengesellschaft Switzerland, asi Brown Boveri &

Cie.,- Baden, Switzerland, a joint-stock company of SwitzerlandApplication May 19, 1933, Serial No. 671,823 In Germany June 1, 1932 11Claims. (Cl. 200-150)` This invention relates in general to circuitinterrupters having pressure pots provided with means for regulating thedischarge of arc extinguishing fluid across the arc in accordance withthe pressure generated within the pot, and more particularly to circuitinterrupters in which such regulated discharge action commences duringthe initial circuit interrupting action.

To accelerate the interruption oi' alternating current arcs in heavyduty circuit breakers the so-called explosion pots as well as otherdevices have been used. Heretofore these explosion pots generally havebeen provided with only one nozzle opening through which the movablecontact rod may move. As long as the movable contact rod is within thechamber the nozzle opening is so restricted that it is difficult todesign the walls of the pressure chamber suiiiciently strong to hold thepressures generated by the arc within the pot.

To overcome this diiiculty explosion pots containing a certain volume ofair have been proposed, the air being compressed by the pressuregenerating arc, however, such arrangements have not proven to bepractical because the turbulence of the liquid within the pot causesmost of the air to be ejected from the pot. Pres- 'sure chambers havingadditional fixed openings for the discharge of gas have also beenproposed, however, such arrangements are not effective to produce avigorous blast of arc extinguishing liquid through the arc when thecurrent to be interrupted is of small magnitude. Pressure chambershaving valve controlled openings for the discharge of gas have also beenproposed, however, in such arrangements the energy of the gas escapingthrough these openings is wasted inasmuch as it is not caused to flowthrough the arc.

It is therefore an object of this invention to provide a circuitinterrupter with a pressure pot having a pressure controlled dischargeopening which utilizes the energy of the discharged iiuid to cause ablast of arc extinguishing iiuid to il'ow across the arc before leavingthe pressure pot.

Another object of the invention is to provide a circuit interrupter witha pressure pot havingA a restricted passageway for a movable contact anda valve controlled discharge opening in com- `munication with anVannular arcing contact member for causing the iiuid discharged throughsaid opening to flow across the points of attachment of the arc on thearcing contact member.

It is an object of the invention to provide a 4circuit interrupter witha pressure pot having a passageway for the movable contact sufilcientlyrestricted so as to eiilciently extinguish an arc at smaller currentsand pot pressures and to provide a means controlled by excessive potpressures caused by greater currents for relieving the excess pressureand utilizing such excess pressure in extinguishing the arc.

A further object of the invention is to provide a circuit interrupter ofthe pressure pot `type with a bushing supported bearing member and apressure pot supporting member having cooperating sockets andprojections 'for preventing the rotation of the pressure pot relative tothe insulating bushing.

A still further object oi' the invention is to 15 provide improveddetails ofvfconstruction of a circuit interrupter of the pressure p ottype various novel features of which will be apparent from thedescription and drawing herein, and will be more particularly pointedout in the claims.

Various illustrative examples of this invention are shown in theaccompanying drawings in which:

Fig. 1 is a sectional side view of a circuit 25 breaker of the pressurepot type embodying features of the invention.

Fig. 2 is a top view of the supporting memberA shown in Fig. 1 detachedfrom the insulating bushing.

Fig. 3 is a sectional side view of the supporting member, valve andcontact assembly taken along line III-III of F18. 2.

Fig. 4 is a sectional side view of a structure similar to Fig. 3 andwithin the scope of the in- 35 vention.

Fig. 5 is a sectional side view of another form of pressure rpotassembly embodying the invention.

y Fig. 6 is a sectional view of a modled form of 40 vsupporting member,valve, and contact structure embodying the invention.

Fig. 7 is a side view of the contact sleeve shown in Fig. 6.

Fig. 8 is a top sectional view of contact and 45 valve structure shownin Fig. 6 taken along the line VIII-VIII.

Referring now to Fig. 1, circuit breaker tank I I contains an arcextinguishing fluid I2 and has an insulating bushing I3 angle to thevertical. The lower end of bushing I3 is provided with a bearing plateI4 secured thereto by suitable means such as cement I5. A truncatedsupporting member I6 is held in engagement with bearing plate Il bymeans of an 55 projecting thereinto at an assembly conductor rod yalsoprovided with a bleeder vent I1 and is prevented from turning relativeto plate I4 by means of projections I8 thereon which cooperate withcorresponding recesses in bearing plate I4. Supporting member I6 isprovided with an axial bore I9 in which the stationary contact structureis mounted as will be-described hereinafter.

Ring member 2i is secured to supporting member I6 in spaced relationthereto by a plurality of stud bolts 48 in a manner better shown inFigs. 2 and 3. The opening through ring member 2| is provided with anozzle member 22 here shown-as of insulating material dening an axialdischarge passageway 23. Ring member 2I is 20 which permits the pressurepot to refill with arc extinguishing fluid by discharging the gasremaining in the top of the pressure pot after a circuit interruptingoperation. An upper contact structure is provided with a butt contact 24detachably secured to contact tube 25 which is slidable in axial bore I9and is biased downwardly by spring 26. An annular valve plate 21preferably of metal closely surrounds contact tube 25 and is biased intoengagement with plate 2I by means of springs 26 in such a manner thatdischarge passageway 23 is normally closed. A conducting ring 26 iswelded or otherwise secured to contact tube 25 and connected to thisring are a' plurality of pigtail conductors 3I which are connected tosupporting member I6.

A pot member 32 preferably of insulating material is secured to ringmember 2| by suitable clamping means such as clamping ringl 33 and bolts35, noting that a gasket 34 is inter-posed between the upper edge of thepot member 32 and ring 2i. Within the pot member perforate baffle plates36, 31, 38 and 33 may be secured in spaced relation by means of aplurality of spacers 4I, 42, 43 and 44 and retaining ring 45. In someinstances it is desirable that the above described baille plates beomitted. The xlower end of pot member 4I is provided with a throatbushing 46 preferably of insulating material adapted to withstand theheat of arc currents. A movable contact rod 41 is adapted to be moved byconventional mechanism (not shown) through the contact openings inthroat bushing 46 and the perforations in baille plates 36 to 39,inclusive, into engagement with butt contact 24, noting that thesebaille plates preferably closely surround contact rod 41 so that themovement of arc extinguishing fluid in a downward direction is limitedwhile the contact rod 41 is within the pressure pot.

Figs. 2 and 3 show more in detail the manner in which ring member. 2I issecured to supporting member I6 by'means of stud bolts 43. It is to benoted that valve plate 21 is provided with a plurality of holes throughwhich stud bolts 43 pass thus serving to guide the movement of valveplate 21. As shown in Fig. 3 the downward movement of contact tube 25 islimitedby conducting ring 2S abutting against the upper face of valveplate 21. A vent passageway 49 from axial bore I6 permits uid withinthis bore to be displaced when contact 24 is moved upwardly. Valve plate21 may be provded with a small vent opening 5|! to permit gases frompassageway 23 to escape from the pot after the circuit breaker hasoperated.

4As to the operation of the circuit breaker disclosed in connectionwith'Figs. 1, 2 and 3, upon downward movement of contact rod 41 an arcwill be drawn between butt contact 24 and the top o! contact rod 41.This arc will generate pressure noting' that while contact rod 41 ismoving through the openings in baiile plates 36 to 39, inclusive, andthrough throat bushing 46 valve control passageway 23 is substantiallythe only exit for arc extinguishing iiuid and gas. When the pressure hasbuilt up sumciently to raise valve plate 21 against compression springs26 a discharge of arc extinguishing uid will iiow from the interior ofpot member 32 through the arc and out of the pot through dischargepassageway 23. As the pressure increases or decreases valve plate 21will raise or lower to control or regulate the eiective cross section ofthe discharge passageway thereby maintaining suflicient pressure .withinthe pressure pot to cause a vigorous blast of arc extinguishing fluidthrough the are. If the arc persists or is reignited after passingthrough a zero current condition the arc extinguishing uid between thevarious baille plates will flow into the arc stream thereby causing anadditional arc extinguishing action. If the arc still persists aftermovable contact member 41 is completely withdrawn from throat bushing 46a downward blast ilow.through the throat of bushing 46 and willextinguish the arc in a manner accomplished by the conventionalexplosion pot construction. It is to be noted that inFig. l the arc willattach to butt contact 24 and will pass through insulat- 'f ing nozzle22 whereas in a structure such as shown in Fig. 3 the arc will attach tothe metal arcing ring 5I after the contacts have separated apredetermined amount and this arc will be acted upon by arcextinguishing iluid owing into passageway 23.

Fig. 4 shows a structure substantially the same as Fig. 3 except thatthe truncated supporting member- I6 is bolted to a bearing plate 53 bymeans of a flanged portion 52. This construction is particularly usefulwhere it is desired to use an oil nlled insulating bushing such as shownby I3. Downward movement of contact tube 25 is prevented by a retainingring 54 which cooperates with a shoulder on contact tube 25.

In Fig. 5 truncated supporting member 55 is provided with projections I6and a threaded hole for assembly rod I1 so that the pressure pot shownin this figure may.be secured to and removed from a bearing plate suchas shown by I4 in Fig. 1. Supporting member 55 is welded or otherwisesecured to a supporting plate 56. A ring member 51 is secured tosupporting plate 66 in spaced relation thereto by means of a pluralityof circumferentially spaced stud bolts 56. An

annular cage member 59 is bolted or otherwise secured to the bottom faceof ring member 51 and is provided with an opening in the upper endthereof in which vtubular contact member 6I is secured. The inner wallsof contact member 6I define a portion of a discharge passageway 66. Aplurality of contact segments 62 are circumferentially arranged aroundtubular contact member 6I and are biased into contacting engagementtherewith by means of upper springs 64. The lower portions of contactsegments 62 are biased laterally into passageway 66 by means of lowersprings 63. An annular ring member 65 preferably of metal is secured tocage member 59 and serves as an arcing contact member, however, it is tobe noted that in some instances it is desirable that this member be madeof insulating material in which event it serves as a baille plate.Passageway 66 is normally closed by valve of arc extinguishing uid Willf plate 61 by means of springs 63 and 53 noting that 75 stop member 1|serves to limit the upward movement of valve plate 61. A plurality ofguide pins 12 are circumferentially spaced around valve plate 61 andserve to guide the movement of this valve plate.

A, shell member 13 as here shown is secured to cage member 59. For lowvoltages this member may be of metal, however, for high voltages it ispreferable that insulating material be used. A throat bushing 14 issecured to shell member 13 by suitable means and is provided 'with acontact passageway therethrough for the movement of movable contactmember 15 with small clearances therebetween. Contact rod 15 is securedto bridging member 16 which is operated by conventional mechanism (notshown).

As to the operation of the apparatus shown in Fig. 5, upon initialseparation of contact rod 15 and contact segments 62 an arc will bedrawn therebetween which generates pressure. When this pressure exceedsa predetermined value contact plate 61 will raise and permit a blast ofarc extinguishing fluid to flow across the arc and through passageway 66to the exterior of the pressure pot. As the pressure within the pressurepot increases or decreases valve plate 61 will raise or lower toregulate the discharge of fluid from the pot by controlling theeilective cross sectional area of the discharge blast. When contact rod15 is withdrawn from throat member 14 an additional blast downwardlythrough the contact passageway in throat member 14 is available forextinguishing any arc that may persist. It is'to be noted that the abovedescribed stationary contact structure affords a novel means forconducting current from a movable member to a stationary member withoutthe use of pigtail connections inasmuch as upper springs 64 bias theupper portion of contact segments 52 into contacting engagement withtubular contact meinber 6|.

In Fig. b', a truncated supporting member 1T is adapted to be secured toan insulating bushing as shown in Fig. 1. Ring member 2| is secured tosupporting member 11 in spaced relation thereto by means of stud bolts18. The opening in ring member 2| is provided with a bushing 19 throughwhich slotted contact tube 8| (more clearly shown in Fig. 7) is adaptedto slide. Contact tube 8| has a conducting ring 29 secured 'thereto andis biased in a downward direction by Contact spring 84. Annular contact82 is removably secured to contact tube 8| and is adapted to cooperatewith movable contact 88 which is provided with an arcing tip. A valvemember 85 is provided with a plurality of projections adapted to extendthrough the slotted portions of contact tube 8| and these projectionsnormally rest upon bushing member 19. Valve spring 8S normally biasesvalve member 85 to the position shown in which passageway 23 through thetubular contact is closed.

By referring to Figs. 6, 7 and 8 it will be seen that upon occurrence ofexcessive pressure generated by an arc drawn between contacts 82 and 88valve member 85 will raise against the pressure of springs 84 and 88inasmuch as conducting ring 29 rests upon the projecting portions ofvalve 85 after contact rod 83 has been withdrawn, thereby opening aplurality of vents for the discharge of arc extinguishing iluid throughthe arc and through passageway 28f`and out of the pot through `the slotsin contact tube 8|. It is thus seen that valve 85 is capable ofregulating the effective cross sectional area of the fluid dischargedfrom the pressure pot in accordance with the pressure within the pot.

Although but a few embodiments of the present invention have beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

It is claimed and Patent:

1. A circuit interrupter comprising a pressure pot containing an arcextinguishing fluid and having a movable contact passageway through oneend thereof, a contact structure mounted l5 adjacent the other end ofsaid pot in axial alinement with said passageway, a contact member ofsubstantially the same cross sectional size as said passageway movablethrough said passageway to draw a pressure generating arc between saidcontacts and within said pot, means including a second dischargepassageway surrounding said contact structure whereby said arcextinguishing iluid flows across the points o1' attachment of said arcon said contact structure and to the exterior 25 of said pot, and valvemeans surrounding a portion of said contact structure and normallyclosing said discharge passageway, said valve means being operable toopen said discharge passageway only when the pressure within said. potexceeds a predetermined magnitude.

2. A circuit interrupter comprising a pressure pot having alinedopenings in the top and botdesiijed to secure by Letters rtom thereofand containing an arc extinguishing iiuid therein, an arcing contactstructure secured a5 to said pot and having an aperture in alinement ywith the alined openings in said pot, a spring biased stationary contactstructure mounted on said pot adjacent the top opening in said pot, a

movable contact member normally extending 40 I through the opening inthe bottom of said pot and the aperture in said arcing contact structureinto engagement with said stationary contact structure and withdrawableto establish a pressure generating arc which attaches to said arcingcontact structure, valve means normally closing the opening in the topof said pot and openable upon generation of a predetermined pressurewithin said pot to permit arc extinguishing fluid to ilow across saidarc and through the aperture in said arcing contact structure andthrough the opening in the `top oi' said pot.

3. A circuit interrupter comprising a pressure pot containing an arcextinguishing iiuid, said pressure pot having axially alined openings inthe top and bottom of said pot, at least one baille plate within saidpot having a hole therein in alinement with said openings, an arcingcontact member secured in the top opening in said pot and provided withan axial passageway therethrough, a resiliently mounted contact memberarranged in said axial passageway so as to define a discharge venttherebetween, a contact rod normally extending through the bottomopening in said pot into engagement with said resiliently g5 mountedcontact member and withdrawable through the opening in the bottom ofsaid pot to draw a pressure generating arc which attaches to said arcingcontact member and causes a pressure blast of arc extinguishing fluid toflow across the points of attachment of said arc on said arcing contactand out of said pot through said discharge vent, and valve meanssurrounding said resiliently mounted 'contact member for preventing theilow of arc extinguishing fluid out of said discharge vent until thepressure within said pot exceeds a predetermined value.`

, 4. A circuit interrupter comprising a supporting member, an annularring member secured to said supporting member in spaced relationthereto, a valve member covering the opening in said annular ringmember, spring biasing means arranged between said supporting member andsaid valve member, a pressure pot member secured to said annular ringmember and having a contact passageway therein, a stationary contactstructure arranged within said pot member concentrically of said annularring member, a contact member movable through said contact passagewayfor connection and disconnection with said stationary contact structure.

5. A circuit interrupter comprising a supporting member, an annularplate member bolted to said supporting member in spaced relationthereto, a valve member covering the opening in said annular platemember, spring biasing means arranged between said supporting member andsaid valve member, a pressure pot member of insulating material securedto said plate member and having a contact passageway therethrough, astationary 'contact assembly secured within said pot member to saidplate member, said assembly comprising a plurality of spring biasedcontact segments annularly arranged to form a passageway communicatingwith the opening in said annular plate and comprising an annular arcingplate forming a portion of said passageway and a contact rod movablethrough said contact passageway and through the opening in said annulararcing plate into engagement with said contact segments.

6. A circuit interrupter comprising'a supporting member, a ring membersecured to said supporting member in spaced relation thereto and havinga centrally located opening therethrough, a spring biased contact memberslidably mounted in said supporting member and arranged to project intosaid opening, a valve member surrounding said contact member andnormally closing said opening, spring biasing means arranged betweensaid supporting member and said valve member, a pressure pot membersecured to said ring member and having a contact passageway,therethrough, and a contact rod movable through said contact passagewayinto engagement with said spring biased contact.

7. A circuit interrupter comprising a supporting member, a ring membersecured to said supporting member in spaced relation thereto and havinga centrally located opening therethrough, an annular arcing contactmember secured to said ring member and having a passageway therethrough,a spring biased contact member slidably mounted in said supportingmember and arranged to project into the passageway in said arcingcontact member, a valve member surrounding said contact member andnormally closing said opening, spring biasing means arranged betweensaid supporting member and said valve member, a pressure pot membersecured to said ring member and having a contact passagewaytherethrough, and a contact rod movable through the contact passagewayin said pot member into engagement with said spring biased contact.

8. A circuit interrupter comprising a supporting member, an annular ringmember secured to said supporting member in spaced relation thereto, atubular contact member extending through the opening in said annularring member and having a plurality of discharge openings therein, avalve member slidable within said tubular contact member, a. springabutting against said supporting member and arranged to normally biassaid valve member to a position wherein said discharge openings areclosed, a pressine pot member secured to said ring member and having ,acontact opening therein, and a contact rod movable through said contactopening to draw an arc within said pressure pot member.

9. A circuit interrupter comprising a supporting member, an annular ringmember secured to said supporting member in spaced relation thereto, atubular contact member slidable through the opening in said annular ringmember and having a discharge passageway therethrough, a spring forbiasing said tubular contact to a limit position, a valve memberslidable within said tubular contact member, a. spring abutting againstsaid supporting member and arranged to normally bias said valve memberto a position wherein said discharge passageway is closed, a pressurepot member secured to said ring member and having a contact openingtherein, arc extinguishing liquid within said pressure pot member, and acontact rod movable through said contact opening to draw a pressuregenerating arc within said pressure pot member.

10. A circuit interrupter comprising a truncated supporting member, aring member secured to said supporting member in spaced relation theretoand having a centrally located opening therethrough, a spring biasedcontact member slidably mounted in said supporting member for limitedaxial movement into the opening in said ring member, flexible currentcarrying conductors connected between said contact member and saidsupporting member, an annular valve member surrounding said contactmember and normally closing the opening in said ring member, springbiasing means abutting against said supporting member for biasing saidvalve member to its closed position, a pressure pot member secured tosaid ring member and having a contact passageway therethrough and acontact rod movable through said contact passageway into engagement withsaid spring biased contact mem- 50 ber.

11. A circuit interrupter comprising a pressure pot having openings inthe top and bottom there.; of and containing an arc extinguishing iluidtherein, an arcing contact structure secured to said pot and having anaperture, a spring biased stationary contact structure mounted on saidpot adjacent the top opening in said pot, a movable contact membernormally extending through the opening in the bottom of said pot and theaperture in said arcing contact structure into engagement with saidstationary contact structure and withdrawable to establish a pressuregenerating arc which attaches to said arcing contact structure, valvemeans normally closing rthe opening in the top of said pot and openableupon generation of a predetermined pressure within said pot to permitarc extinguishing fluid to iiow across said arc and through the aperturein said arcing contact structure and through the open- 7

